Caffeine & Sleep: How Long Does Caffeine Keep You Awake?

July 7, 2023 - Katie McCallum

Instead of counting sheep you're counting hours of sleep. Specifically, the number of hours you're not getting. Or, maybe you're counting the number of hours you might get if you fell asleep right now. Nope, still not asleep.

Was it that latte you had after lunch??

You know caffeine can keep you awake, and there are the obvious times to avoid it. (Right before bed, for instance...just in case...)

But is an afternoon pick-me-up really a problem? At the time, it felt like you needed it just as much as the sleep you're not getting now.

"It's very important to be sure you're getting quality sleep," says Dr. Rashad Ramkissoon, a primary-care physician at Houston Methodist. "Certain afternoon and evening habits can get in the way of that, and caffeinated beverages are one prominent example."

So, when it comes to that gray area between late morning and early evening, how late is too late to drink that coffee you so desperately need — or even just a soda or iced tea with dinner — without it affecting your sleep?

How does caffeine work?

Once consumed, caffeine is very quickly absorbed and distributed throughout your body, including to your brain. It's here that caffeine elicits its most classic effect — helping keep you alert and awake.

"Caffeine works by blocking sleep-promoting receptors in your brain called adenosine receptors," says Dr. Ramkissoon. "It can do this because, structurally, caffeine looks very similar to adenosine, the molecule that usually binds to these receptors."

Continue reading the houstonmethodist.org article

Video taken from TEDEd

Answer the questions 

• What are the origins of caffeine?
• How much caffeine is consumed every year?
• Where can caffeine be found?
• How do caffeine and adenosine relate?
• Can you name pros and cons of its consumption?
• Can you explain how and why caffeine keeps us awake?
• What happens if you stop taking caffeine?
• Write a paragraph based on the reading and the video.